a) Field of the Invention
The invention is directed to a jack plug with a contact tip which is provided at the free end and followed by a connection part which is received by a tubular shaft of the jack plug, wherein the contact tip is electrically insulated from the shaft and the shaft has, at the side remote of the contact tip, a handle part through which the connecting cable runs.
b) Description of the Related Art
Jack plugs of this type are known in many constructional forms. All of them share the common feature that they have a shaft with an onion-shaped contact or contact tip provided at one end of the shaft and a handle part at the other end of the shaft. In every case, the contact tip has a contact needle which is received by the shaft and is electrically insulated therefrom. The center conductor of the connecting cable is fixed at this contact needle so as to be connected therewith in an electrically conducting manner. For this purpose, a bore hole of short length is provided in the contact needle at the handle end, wherein the conductor to be connected is inserted into this bore hole. The conductor can be connected with this bore hole in an engagement through the agency of material or by deformation. Further, it is known to squeeze in the conductor between the inner end of the contact needle and the insulating sleeve enclosing the contact needle. Further, it is already known to arrange a clamping screw at the inner end of the Contact needle, wherein the center conductor mentioned above can be connected by means of this clamping screw. Examples for all of these constructions are shown in the following published materials: AT-PS 2 935; AT-PS 6 395; AT-S 22 389; AT-PS 43 309; AT-PS 115 980; DE-PS 561 322; DE 38 34 172 A1; DE 42 27 921 A1; DE 44 14 012 C1; U.S. Pat. No. 3,656,089; U.S. Pat. No. 4,018,501; U.S. Pat. No. 4,275,946; U.S. Pat. No. 4,275,947; U.S. Pat. No. 4,335,930; U.S. Pat. No. 4,647,135; U.S. Pat. No. 2,878,459.
Two-pole connector plugs of the kind mentioned above, known as jack plugs or, in English, phone plugs, originate from telephone technology and at present are used chiefly in music electronics and electroacoustics as economical and robust plugs in unbalanced circuits, as they are called, e.g., electric guitars, instruments, sound pickups or electronic musical instruments such as synthesizers and keyboards. The accompanying cable is usually coaxial with an inner conductor of stranded wire, a rather sturdy low-impedance insulation, preferably made from polyethylene, an outer conductor arranged over this insulation in the form of a shielding braid or a shielding spiral (braided shielding or spiral shielding) covered by a plastic jacket for protecting the cable.